The population of a city is growing at an average rate of 3% per year. In 1990, the population was 45000

P (y) = 450000 (1.03) ^ (y-1990)

A. N (y) = 45,000*1.03^ (y-1990)

N (y) = population in year y,

45,000 = poppulation in 1990,

1.03 = yearly growth factor,

y = year y

b. 2,007-1,990=17 years

N (17) = 45,000*1.03^ (17) = 74,378.14

c. 2N=N*1.03^ t

2=1.03^t

t=log (2) : log (1.03) = 23.4

23.4+1,990=2,013.4

d. 2 = (1+r) ^10

r=2^ (1/10) - 1) * 100=7.18%